[unreadable] The main objective of this project is to design, fabricate and experimentally research the application of capillary x-ray optics as a means of elevating the dose rate of the radiation produced by a needle-based x-ray system. The goal is to reach the dose rate of 10 Gy/hour at a distance 5 mm from the pseudo-target. The other objective is to apply capillary x-ray optics to creating a high intensity x-ray source that can produce a narrow (diameter lesser than 1.0 ram) quasi-parallel x-ray beam for possible usage in neurosurgery. The offered x-ray system is based on an insertable needle x-ray source with which the x-ray beam properties such as (energy), intensity (delivery time), and beam orientation (exposure region) could be controlled. To achieve the aims of the project I, we will: (1) design, build and test a capillary x-ray lens, (2) incorporate the capillary lens into an optical collimator, (3) integrate the collimator into a prototype needle-based x-ray system; (3) perform calculations of x-ray dose distribution from the pseudo-target using Monte-Carlo simulation; (4) carry out experiments to characterize dose and dose rate distribution of the radiation produced by the pseudo-target, and (5) measure scattering of a sharply focused x-ray beam in tissue imitating materials. [unreadable] [unreadable] Phase II of the project will be devoted to building an extended energy range (8keV-60 keV), high dose rate x-ray system incorporating new x-ray focusing/collimating optics. A treatment planning system for the needle x-ray device will be developed. [unreadable] [unreadable]